The people behind Firefox are planning a big marketing push for the latest version of the open source web browser.

Firefox 1.5 is due to be available for download on 29 November, marking the end of a thriving year for the browser.

Analysts say Firefox has grabbed a 10% share of the browser market and it claims to have a core of 40-50 million dedicated users.

Firefox maker Mozilla is now planning more regular updates and to take swift action on security lapses.

Engine overhaul

The Firefox web browser had its first birthday on 9 November 2005 and in the last 12 months has been downloaded by a huge number of web users.

In early November, it celebrated its 100 millionth download.

The last year has been phenomenal in terms of adoption, demand and the feedback we receive from a growing number of people

Chris Beard, Mozilla

Over the past 12 months, Firefox has chipped away at the hold that Microsoft's Internet Explorer browser has over web users.

Figures released in early November suggest it is now on 10% of web users' computers. But Microsoft's Internet Explorer still leads the field with a global share of around 85%.

Firefox's popularity has been helped by the fact that users can contribute to how it develops. Many have written extensions that add specific functions to the browser, such as a RSS feed reader.

"The last year has been phenomenal in terms of adoption, demand and the feedback we receive from a growing number of people," said Chris Beard, vice president of products at the Mozilla Corporation which oversees Firefox development.

The Mozilla Foundation was started by browser maker Netscape and it became a non-profit company in order to drive development of the software.

Mr Beard said the user base tended to be concentrated among the biggest users of the net but now Mozilla was planning a push to get the software adopted by more consumers.

He said it was looking to work with net service firms and computer makers to get the browser in front of users who had not seen it before.

At the same time, it will step up efforts to spread the word about Firefox and is seeking videos from fans of the ways they use the software.

Many more websites were also tweaking their webpages to ensure they render properly. Mozilla will also put tools in the next release of the browser that let people report webpages that look strange when viewed via Firefox.

At the same time Mozilla is planning regular updates to Firefox every six to nine months and to move quickly to close security loopholes.

The release of Firefox 1.5 marks a big overhaul of the browsing "engine" inside the program, Mr Beard told the BBC News website.

New browsers are also continuing to appear. Most recently a browser called Flock launched that tries to make it easier for users to manage what they do on the web, such as remember places of interest and store pictures, in one place.